BALTEX Phase II 2003 – 2012. Science Framework and ...

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BALTEX Phase II Science Framework and Implementation Strategy
The objectives of BALTEX Phase II are shortly outlined as follows:
Objective 1:
Better Understanding of the Energy and Water Cycles over the Baltic Sea Basin
Potential Activities
• Regional Analysis and Re-analyses for Different Variables for specific Purposes
• Further Development of Models and Model Improvement
• Closing the Energy and Water Budget on a High Level of Confidence
• Improvement of Quantitative Precipitation Forecast
• Evaluation of Models and Data Sets for their Use in Climate Impact Analysis and
Environmental Issues
While BALTEX research has met to a large extent BALTEX Phase I objectives, gaps still exist and
further research is needed for a more comprehensive fulfilment of the original BALTEX aims. Future
BALTEX research related to this objective will therefore mainly contribute to further improving the
physical understanding of processes, related modelling capabilities, and the quantitative estimation of
important water and energy cycle parameters. Major goals include the evaluation of regional models
with increasing and unprecedented detail with the particular perspective to support climate and
environmental studies and to develop strategies for climate and environmental impact assessments.
BALTEX will continue to establish and better explore more comprehensive observations from the
entire Baltic Sea basin, including new satellite data. The further development of modules of coupled
regional models for the atmosphere, the land surface including rivers and lakes, and the Baltic Sea
including sea ice will be pursued. While some basin-wide estimates of atmospheric water transport
divergence derived from re-analysis data sets, agree coincidentally within 10 to 20 % with basin-wide
runoff estimates, individual components of the water and energy cycle show sometimes drastic
mismatch and even unphysical direction of fluxes. A major future goal therefore remains to establish
more reliable estimates of budgets and fluxes, i.e. to close the energy and water budgets at lower
uncertainty.
Objective 2:
Analysis of Climate Variability and Change since 1800, and Provision of Regional
Climate Projections over the Baltic Sea Basin for the 21 st Century
Potential Activities
• Reconstruction History of Climate in the past 200 Years as well as detailed Re-analysis of
“Weather” during the past 40 Years
• Detection and Attribution of Climate Change
• Scenarios based on Evolving Global and Regional Forcing and Response
• Assessment of Climate Change for the Baltic Sea Basin
Extended observations of climate parameters are available in the region, which should be exploited in
concert with model studies. As for most regions, there are specific regional challenges of global
climate change for the Baltic Sea basin. The combined effects of climate change and socio-economic
changes are largely unknown at present. BALTEX Phase II will contribute to the detection of regional
climate change in the Baltic Sea basin, and to a better understanding of the physical mechanisms that
are behind climate variability and change. One aim is to discern between natural and anthropogenic
causes and thus to contribute to attribution studies. Another is to study the contributions of large-scale
control and locally/regionally generated forcing on the Baltic Sea basin climate. A further major aim
for BALTEX Phase II is to develop projections of future climate variability and change by means of
sensitivity analyses and model studies.